Background: CD1D presents glycolipid antigens to invariant natural killer T (iNKT) cells. The role of CD1D in the development of peptic ulcer and gastric cancer has not been revealed, yet.Objective: To clarify the expression of alternatively spliced variants of CD1D in peptic ulcer and gastric cancer.Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC), according to their endoscopic and histopathological examinations.H. pylori infection was diagnosed by rapid urease test and histopathology. The expression levels of V2, V4, and V5 spliced variants of CD1D molecule were determined by quantitative Reverse Transcriptase PCR.Results: Relative gene expression levels of V4 were higher in GC patients (n=37) than those in NUD (n=49) and PUD (n=51) groups (p<0.05 and p<0.01, respectively). Moreover, GC patients showed higher expression levels of V5 compared to NUD and PUD groups (p<0.001 and p<0.001, respectively). Positive correlation coefficients were attained between V4 and V5 expression in patients with PUD (r=0.734, p<0.0001) and GC (r=0.423, p<0.01), but not in patients with NUD. Among NUD patients, the expression levels of V4, but not V5, were higher in H. pylori -positive patients than in H. pylori negative ones (p<0.01).Conclusion: Collectively, both membrane-bound (V4) and soluble (V5) isoforms of CD1D were over-expressed in gastric tumor tissues, suggesting that they are involved in anti-tumor immune responses.

Background: The CD1 family is less variable trans membrane antigen presenting molecules related to the MHC molecules. CD1a and CD1e genes are the most polymorphic ones associated with autoimmune diseases. The aim was to better clarify the map of CD1 genes in Southwest Iranian normal population for implications in vaccine design.Methods: In this study we investigated the polymorphism of CD1a, CD1D and CD1e in 311 healthy individuals from Fars Province in Southwest of Iran by PCR-SSP method.Results: Six of individuals had homozygote CD1a 01/01 genotype and 248 had homozygote CD1a 02/02 genotype. CD1D was found to be monomorphic with all tested individuals showing CD1D 01/01 genotype. Hundred and eleven individuals had homozygote CD1e 01/01 genotype and 48 had homozygote CD1e 02/02 genotype. The frequencies of CD1a 01 and CD1a 02 alleles were 11% and 89% while the frequencies of CD1e 01 and CD1e 02 alleles were 60.1% and 39.9%, respectively. Consistent with previous reports on other genes, a high degree of similarity in CD1a and CD1e allelic distribution was observed between Southwest Iranians and other Indo-European populations. How-ever, the allelic frequency of the CD1a and CD1e alleles showed a significant difference from those of Chinese Han and She populations.Conclusion: These data are notable in the light of relatively recent genetic admixture along the Silk Road. Considering the significance of CD1 alleles in some autoimmune and infectious diseases and with the admixed nature of Iranian population, mapping the distribution of CD1e alleles in different regions of Iran can be useful in future designing of preventive and therapeutic vaccines.